1. Technical Field
The present invention relates to a display device which displays a video screen on a display surface and performs display control of the video screen in accordance with an operation to the display surface, a control method of the display device and a program.
2. Related Art
Hitherto, as this type of display device, there is known a display device which includes many sensors to detect a locus of a character or the like written on a writing surface of an electronic board by a pen-like writing instrument, recognition means for recognizing the character and figure drawn on the writing surface based on image data of the locus detected by the sensors, command execution means for editing the recognized character and figure in accordance with an edit command, and projection display means for displaying the edited character and figure on the writing surface (see JP-A-5-330289).
In this display device, edit commands such as erasure, movement, copy, and call are prepared, and the command execution means executes the erasure, movement or copy of the character and figure in accordance with the edit command inputted by the writing instrument.
At school or the like, as in a lesson of how to use a triangle ruler or a protractor, there is a case where a stationery is suitably rotated, and its usage is taught. In such a lesson, when the related art display device is used, since a figure can not be rotated, there is a problem that after a figure is drawn, a figure obtained by rotating the figure must be additionally drawn. Besides, although it is conceivable that a command to rotate a figure is installed as an edit command of the pen-like writing instrument, there is a problem that the number of edit commands of the pen-like writing instrument increases, and the operation becomes complicated.